Control devices for fuel injection pumps for use in internal combustion engines



L. LOHR 32,666 CONTROL DEVICES FOR FUEL INJECTION PUMPS FOR USE IN Dec. 6, 1966 INTERNAL COMBUSTION ENGINES Filed Aug. 31, 1964 United States Iat 3,289,660 CONTROL DEVICES FOR FUEL INJIEQTION PUMPS FOR USE IN INTERNAL COMBUS- TliON ENGINES Ludwig Lohr, Lampertheim, Germany, assignor to Farymann Diesel, Farny & Weidmann oHG, Lampertheim, Germany, a German company Filed Aug. 31, 1964, Ser. No. 393,316 Claims priority, application Germany, Sept. 18, 1%3, F 40,781 6 Claims. (Cl. 123-139) The invention relates to control devices for fuel injection pumps for use in internal combustion engines. More specifically the invention is concerned with a manually adjustable control device for temporary adjustment in order to produce a fuel injection of extra-normal quantity when starting an internal combustion engine, said device cooperating with a regulating rod, which when the load on the internal combustion engine increases, is moved in the direction of its longitudinal axis towards the con trol device.

Known devices of the aforesaid kind, which are generally movable at right angles to the longitudinal axis of the regulating rod, are rather expensive to make, and only with difficulty do they permit adjustment of the normal injection quantity. They therefore often require a special adjustable stop for the normal quantity fuel injection, which represents. an additional expenditure.

According to the present invention there is provided a control device for a fuel injection pump for use in an internal combustion engine having at least one cylinder, the pump having a regulating rod which, in operation, is movable axially in one direction towards said device when loading of the engine is increased, said device comprising:

(i) A stop carrier rotatable about an axis of rotation located approximately parallel to the axis of the regulating rod;

(ii) Spring means for urging said stop carrier in one direction of rotation; and

(iii) An end stop surface of said stop carrier for adjustably varying a stop position for the regulating rod, said surface being remote from said axis of rotation of said carrier; whereby when said spring means is tensioned by rotating said stop carrier in a direction opposite to said one direction of rotation, said stop surface assumes a position which will allow an extra-normal quantity of fuel to be injected into said cylinder of said engine.

In one embodiment of the invention the stop surface is formed by the end face of a stop bolt screwed into the stop carrier obliquely to the axis of rotation of the carrier.

Furthermore the stop bolt may be adjustable by certain angular amounts, the stop bolt having a polyhedral portion, on the faces of which rests the hook-shaped ends of a cut-open spring ring lying in an annular groove of the stop carrier.

The device may be adjustable for normal, i.e. warm, engine running by providing the stop bolt with a screwdriver .slot accessible from the outside.

For a better understanding of the invention, and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, wherein:

FIG. 1 is an end view of one embodiment of the present invention;

FIG. 2 is a section on the line 11- 11 of FIG. 1;

FIG. 3 is an end view of the regulating rod illustrated in FIG. 2 seen in the direction of the arrow III; and

FIG. 4 is an end View, partly in section of the stop carrier illustrated in FIG. 2, as seen in the direction of the arrow IV.

In the drawings, an injection pump 2 is mounted in a housing 1 of an internal combustion engine, not shown, the pump having a regulating rod 3, which can assume the position shown in unbroken lines in FIG. 2. The rod 3 assumes this position for the injection, into the cylinder of the engine of a normal quantity of fuel, when a governor spring, not shown, of a speed governor, also not shown, presses the rod against an end face 5 of a stop bolt 4. When the rod 3 assumes the position shown in broken lines in FIG. 2, which it assumes for the injection of an extra quantity of fuel, the end face 5 assumes the position shown in broken lines in FIG. 3. The stop bolt 4 has a cylindrical portion 6, a foursided portion '7, and a screwthreaded portion 8, and is screwed into a generally cylindrical stop carrier 10 obliquely to the axis of rotation 9 of said stop carrier. The stop carrier Ill is inserted for rotation about the axis 9 in a sleeve 11, which is pressed into a cover 12. A rubber ring 13 serves for oil sealing. Riveted to the stop carrier 10 is a lever 14, which can assume the position shown in unbroken lines in FIG. 1 for the injection of a normal quantity of fuel, and which also can assume the position shown in broken lines in FIG. 1, for the injection of an extra quantity of fuel. The lever 14 has a joint 15, which, on the movement of an operating rod or pull, not shown, applied to a point 16, from the normal quantity injection position to the extra quantity injection position, is rigid, but which bends however in the reverse direction of movement. The lever 14 is bent at one end as indicated at 17, the bent-over end being positioned in an arcuate depression 18 of the cover 12 thus forming a stroke limitation for the lever 14. One end of a torsion spring 19' engages the lever 14 and hence the stop carrier 10, and the other end of the spring is pushed into a bore 26 of the cover 12. In an annular groove 21 of the stop carrier 10 lies a cut-open spring ring 22, hooked spring-ends 23 of which lie in contact with the faces of the four-sided portion 7. The stop bolt 4 is provided with a screwdriver slot 24, which is accessible from the outside, as can be seen from FIG. 1.

The mode of operation of the device is as follows:

On starting the internal combustion engine, the lever 14 is moved by hand into the position shown in broken lines in FIG. 1, thus tensioning the torsion spring 19. Since the force exerted by the centrifugal weights of the speed governor at the low starting speed is small compared with the force of the governor spring, the regulating rod 3 will be moved in the direction of its longitudinal axis 25 in the plus direction (-1-) of the double arrow shown in FIG. 2. Since, in the position described, the stop face 5 has been brought out of range of the regulating rod 3 (see the position shown in broken lines in FIG. 3), the regulating rod moves out into the extra quantity injection position, as shown in broken lines in FIG. 2. Its stroke is here limited in the injection pump, in a manner not more fully described. Once the regulating rod is in the extra quantity injection position, it is immaterial whether the operator keeps the lever 14. in the extra quantity injection position or in the normal quantity injection position. If the latter is the case, the joint 15 bends, while the cylindrical outer surface 6 comes to bear against the regulating rod 3. Under the effect of the extra normal quantity injection, the internal combustion engine starts easily and soon reaches a speed, at which the force exerted by the centrifugal weights of the speed governor exceeds the force of the governor spring, the regulating rod 3 being thereby moved in the minus direction of the double arrow shown in FIG. 2. The previously firmly held stop bolt 4 is thereby released by the regulating rod 3 and the torsion spring 19 returns the lever 14 to the starting position. If the internal combustion engine is now put under load, the regulating rod finds its normal stroke limitation at the position shown in unbroken lines in FIG. 2 of the stop face 5. By means of the slot 24, the normal quantity injection position can be adjusted with the engine running, clearly perceptible quarter turns being obtained by the action of the spring ends 23,

The stop carrier may also serve as an extra quantity injection stop. For example, its innermost end face may be constructed as extra quantity injection stop face, that is to say, the said face of the carrier limits the movement of the regulating rod in the direction of the axis of the rod towards the carrier.

I claim:

1. Apparatus for controlling a fuel injection pump of an internal combustion engine, said apparatus comprising in combination: a control rack movable longitudinally in one direction in response to loading of the engine for controlling fuel quantities injected by the fuel injection pump, and a control stop device, said control stop device being independent of said control rack and comprising a stop carrier, means for mounting said stop carrier for rotation between first and second positions about an axis disposed substantially parallel to the longitudinal axis of said control rack, and spring means for urging said stop carrier in a direction of rotation from said second position towards said first position, there being bolt means mounted on said stop carrier and defining an end face forming a stop surface which is remote from said axis of rotation of said stop carrier and which, when said stop carrier is in said first position, lies in the path of longitudinal movement of said control rack in said one direction to define a limiting position of said control rack for injection of normal quantities of fuel by said pump, and said stop surface, when said stop carrier is in said second position, being remote from said path of longitudinal movement of said control rack to permit longitudinal movement of said control rack in said one direction beyond said limiting position for injection of increased quantities of fuel by said pump, and including means associated with said stop carrier for adjusting the position of said stop surface relatively to said stop carrier and thereby also said limiting position of said control rack.

2. Apparatus according to claim 1, wherein said bolt means comprises an elongated, substantially cylindrical member mounted on said stop carrier obliquely to said axis of rotation of said stop carrier.

3. Apparatus according to claim 2, wherein said elongated member is formed at a portion remote from said stop surface with an external screw thread which engages an internal screw thread formed in said stop carrier, rotational movement of said elongated member permitting adjustment of said position of said stop surface relatively to said stop carrier and thereby also said limiting position of said control rack.

4. Apparatus according to claim 3, wherein intermediate said stop surface and said external screw thread, said elongated member is formed with a portion having at least three substantially planar surfaces, extending longitudinally of said elongated member, and including spring means engaging at least one of said substantially planar surfaces for retaining said elongated member against rotation.

5. Apparatus according to claim 4, wherein an end portion of said elongated member opposite said stop surface defines a slot disposed diametrically of said end portion for cooperation with a screw driver for imparting rotational movement to said elongated member, there being means permitting access to said slot from the exterior of said control stop device.

6. Apparatus according to claim 1, and including a lever connected to, and extending radially of, said stop carrier, said lever having a pivoted joint between opposite ends and means to limit hinging of the lever about the joint in a direction opposite to that in which said stop carrier is urged by said spring means.

MARK NEWMAN, Primary Examiner.

LAWRENCE M. GOODRIDGE, Examiner. 

1. APPARATUS FOR CONTROLLING A FUEL INJECTION PUMP OF AN INTERNAL CONBUSTION ENGINE, SAID APPARATUS COMPRISING IN COMBINATION: A CONTROL RACK MOVABLE LONGITUDINALLY IN ONE DIRECTION IN RESPONSE TO LOADING OF THE ENGINE FOR CONTROLLING FUEL QUANTITIES INJECTED BY THE FUEL INJECTION PUMP, AND A CONTROL STOP DEVICE, SAID CONTROL STOP DEVICE BEING INDEPENDENT OF SAID CONTROL RACK AND COMPRISING A STOP CARRIER, MEANS FOR MOUNTING SAID STOP CARRIER FOR ROTATION BETWEEN FIRST AND SECOND POSITION ABOUT AN AXIS DISPOSED SUBSTANTIALLY PARALLEL TO THE LONGITUDINAL AXIS OF SAID CONTROL RACK, AND SPRING MEANS FOR URGING SAID STOP CARRIER IN A DIRECTION OF ROTATION FROM SAID SECOND POSITION TOWARDS SAID FIRST POSITON, THERE BEING BOLT MEANS MOUNTED ON SAID STOP CARRIER AND DEFINING AN END FACE FORMING A STOP SURFACE WHICH IS REMOTE FROM SAID AXIS OF ROTATION OF SAID STOP CARRIER AND WHICH, WHEN SAID STOP CARRIER IS IN SAID FIRST POSITION, LIES IN THE PATH OF LONGITUDINAL MOVEMENT OF SAID CONTROL RACK IN SAID ONE DIRECTION TO DEFINE A LIMITING POSITION OF SAID CONTROL RACK FOR INJECTION OF NORMAL QUANTITIES OF FUEL BY SAID PUMP, AND SAID STOP SURFACE, WHEN SAID STOP CARRIER IS IN SAID SECOND POSITION, BEING REMOTE FROM SAID PATH OF LONGITUDINAL MOVEMENT OF SAID CONTROL RACK TO PERMIT LONGITUDINAL MOVEMENT OF SAID CONTROL RACK IN SAID ONE DIRECTION BEYOND SAID LIMITING POSITION FOR INJECTION OF INCREASED QUANTITIES OF FUEL BY SAID PUMP, AND INCLUDING MEANS ASSOCIATED WITH SAID STOP CARRIER FOR ADJUSTING THE POSITION OF SAID STOP SURFACE RELATIVELY TO SAID STOP CARRIER AND THEREBY ALSO SAID LIMITING POSITION OF SAID CONTROL RACK. 